Screw and nut mechanism



April 15, 1952 D LE 2,592,889

SCREW AND NUT MECHANISM Filed Feb. 20, 1950 3nventor DcWiJ @7171; Q7 KM C(ttomeg Patented Apr. 15, 1952 UNITED STATES PATENT OFFICE 2,592,8 n NUT Dana 'Giiinley, Kansas fifty, laiiiiliatioii i ebtiisry 20, 19st, strains; iii-fist chime (o1.

airt e 'e .e where t :am h assure tin il. e re i lvfiat t t d nl i-ei u W fi e m nhance ent: he time .W f j ub tenfielwbfe ife.9 e m ns antl rele es h wo ay n t 91. b t' s tibh, t e c m at? .ium'bl u 9H oberators hand, etc, any of which inay amage the wgrk or injure the operator The objects or t e inve t-6n e c ns d l2! yei tse threading ofthe parts as will hereinafter more tie iler ii' r e a v.

Another object of the invention;is to produce a Quickacting ,g'ivice wmeh s riotlimi'tedto one or two turns of I the mutilated threaded member for the aiiplication of clamping pressure. The device of the present invention, n the other hand, may be designed to apply clamping pres" sure requ ring extended (longitudinal travel so that a kink'or bend may be taken out of a work iiie'ce to be straightened Without a resetting or is e h- .Y v i a a With the general object's named in view and others will hereinafter appear, the invention consists in certain novel and useful features of construction and organization of parts as hereinafter described and claimed; and in order that it may be fully understood, reference is to be had to the accompanying drawing in which:

Figure 1 is a side elevation 'of a 'c 'clamp embodying the invention, the device being partially? broken away to show a fragment-in central vertical section;

Figure 2 i's a top plan view of the device shown in Figure 1-, but with the work omitted. v

Figure 3 is a cross section through the mii'times clamp screw.

Figure i4 is an end view of the travelling clamp sleeve which is internally and externally rversely threaded.

Figure 5 1s an end view of the clarhii siesta as it may apnearin process ofrnanufacture.

In the, said drawing, where like reference characters identify corresponding parts in all of the figures; l is the-frame if a ti -clamp provided at one end with a clamping anvil 2, receiving the work W. The frame is reinforced by a rib 3 and at its upper end terminates in a head 4 which is internally threaded with a right-hand thread 5 as illustrated.

The internal threads 5 of the head 4 are engaged with the external threads 6 of a tubular clamp sleeve 1. For purposes of illustration the 2 threads 5 and 6 are shown as iight=hand; that is when sleeve I is rotated to the right, thesleev will travel down toward the anvil 2. Adapted for longitudinal travel through a threaded bore in the sleeve 7, "is a clamp screw 9 having is switched clam foot 3 at its lower nd and a clamping handle It at its upper end; The screw 9 is formed for substantially its full length with a mutilated thread H which is the reverse of .top or the nee 4-, the shimmerin the threads 5 and 6. namely; as illustrated, a -1!t"- hand thread;

The thread H is shown as extending through an are of on the screw 9, but this length is subject to change as it is "a matter of design to meet contemplated loads, the balance of the thread being broached or otherwise cut away sown to the plane of the root of thread H b5? preference. In order to cooperate with the clamp screw 9 and its mutilated thread I l, the sleeve 1 is formed with a central bore, divided into the following s'c'tions, in the proportions chosen for illustration: an arc of 90, having a ieft' hand thread 12 to "ennie'sh with the left=hand thread 'I I; an arc of "99 broached'or otherwise cut awasi on a radius slightly exceeding that of the root of thread izito provide an opefi space or area 43 through whicli'the thread [I of screw Elma-3'7 freel v reciprocate for qliick 'sctting pur oses; and an uh thlafld area of Struck on a "slightly 'greatr than the crest of thread 12 whereby shoulders l5 and [6 are provides rot segment with the ends br ne airs-as I, I

one c nvenient means of makijr'igthe internal breach away io-p'rovise area 13; the other -180 bi'ng absence is at I; s ngers a This broached area now; be -filled "with an iiii'thraded see-ties i'n dottedliiies lama 4,- wmch may be sweatcd iew position. or the interested segues in some lines. be refine by fllliiig the masses with not nearer those aafistittioss ere stasis to the "siesta ns at out it be tha be limited b" i-i'abutmeri't blate i1 -13 to the face or "sale head as show in-Fi res 1 time. Inthe prbisortiohs "ortiie devise ii trated, continuous clamping pressure ma be ab plied a distance substantially equalling the length of the sleeve 1 as will hereinafter appear, without a resetting of the clamp.

With a clamp or vise such as shown, at the start of a clamping operation it is preferred the sleeve 1 be in abutment with plate I! so that its full length will be available for clamping purposes if needed. Assuming sleeve 1 has been started from the position just indicated and work W has been positioned on anvil 2. The operator now lines up mutilated threads H with the space [3 in sleeve 1 and can thus quickly position the foot 8 in contact with work W. The operator now imparts right-hand rotation to screw 9 and threads H and i2 will enmesh if they happen to be in alignment. If these threads do not initially enmesh continued rotation of screw 9 will cause their abutting ends to rotate the sleeve I. Under maximum misaligned conditions the resultant travel of the sleeve 1 a linear distance equal to the pitch of threads 1! and I2, will bring about alignment of said threads.

Threads H now move into threads i2 and, as-' suming continued right-hand rotation of the screw 9, the enmesment of threads ll and I2 will effect a backing away or release of pressure a linear distance corresponding to one-fourth of the pitch of threads i i and I2 in the proportions illustrated. By this time, however, the ends of threads 1 I will have contacted the fixed abutment 15. From this point on continued right-hand rotation of screw 9 causes rotation of sleeve 7 to clamp or compress the work W. In the drawing, it is assumed continued clamping pressure has been applied to compress the work the linear distance between the upper dotted end of the sleeve 1 and the abutment late Figure 1.

Assume the work W is under tension in Figure 1 and the clamp is to be released. With the mutilated screw devices of the prior art, this clamping strain is instantly, rather than gradually, released. With the present invention, however, the following sequence of operations will occur, due to the reverse threaded relationship of the parts. If the pressure against the foot 8 has been such that the work has been clamped to the desired degree, left-hand rotation imparted to the screw 9 will tend to increase this pressure as threads H and i2 are lefthand, but since the desired limit of pressure has been reached, there will be no relative change in the position of threads I! and 12 as they are in effect locked together. Thus left-hand motion is imparted to sleeve 7 to rotate same on threads 5 and 5 to gradually release the clamping strain by backing away foot 8. As soon as the pressure or strain has been released as described, mutilated thread I I can be lined up with space l3 for quick release ofwork W. on the other hand, if the work W was not initially tightly clamped, threads ll cannot be lined up with space l3 until travel against the work has been completed, when the above sequence of operations will occur. In other words as long as there is any load on the threads H and 42 they are locked against relative movement which might result in the forcible release of clamping strain.

From the above description and drawing it will be apparent that I have produced a device embodying all of the features of advantage set forth as desirable; and while I have described and illustrated the preferred construction, it is to be understood that I reserve the right to all changes within the spirit and scope of the appended claims.

I claim:

1. A quick-acting clamp comprising an internally threaded head, an externally threaded sleeve in threaded engagement with the head and formed with a bore having a section threaded reversely from its external threads, the internal bore through said sleeve, at opposite ends of its threaded section, terminating in an unthreaded arcuate section struck on a radius slightly greater than the crest of its threaded section and in an unthreaded arcuate section cut away on a radius slightly exceeding that of the root of its thread, respectively, and a clamp screw within the bore of the sleeve having a mutilated thread movable into and out of mesh with the mutilated thread of the sleeve.

2.A quick-acting clamp comprising an internally threaded head, an externally threaded sleeve in threaded engagement with the head and formed with a bore having a section threaded reversely from its external threads, the internal bore through said sleeve, at opposite ends of its threaded section, terminating in an unthreaded arcuate section struck on a radius slightly greater than the crest of its threaded section and in an unthreaded arcuate section cut away on a radius slightly exceeding that of the root of its thread, respectively, and a clamp screw within the boreof the sleeve having a mutilated thread movable into and out of mesh with the mutilated thread of the sleeve.

3. A quick-acting clamp comprising an internally threaded head, an externally threaded sleeve in threaded engagement with the head and formed with a bore having a section threaded reversely to its external threads and an unthreaded section adjoining the threaded section and struck on a radius slightly greater than the-crest of its threaded section, and a screw having a mutilated threaded section extending through said bore with its threads movable into and out of engagement with the threads of the sleeve, said bore having an additional unthreaded arcuate section cut away on a radius slightly exceeding that of the root of its threaded section.

DAVID GRIMLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 754,962 Bennett Mar. 22, 1904 783,845 Munro Feb. 28, 1905 898,604 Rivers Sept. 15, 1908 978,990 Kirkpatrick Dec. 20, 1910 1,045,745 Raes Nov. 26, 1912 1,382,247 Schafer June 21, 1921 2,1332% Smith Nov. 29, 1938 2,247,552 Santen July 1, 1941 2,339,271 Ulanet Jan. 4, 1944 2,372,727 Manning Apr. 3, 1945 FOREIGN PATENTS Number Country Date 418,391 Great Britain Oct. 24, 1934 

